No other elevated road currently under construction shows signs of structural distress, checks that followed the collapse of an uncompleted viaduct in Changi showed.

The Building and Construction Authority (BCA), in response to queries from The Straits Times filed two weeks ago after the July 14 Changi viaduct incident, said: "As a safety precaution, BCA has conducted checks on other road structures above ground that are currently under construction.

"Our checks confirm that there are no signs of structural distress in any of these viaducts under construction."

The Land Transport Authority (LTA) said there are three elevated road projects in progress.

They are a flyover from Seletar West Link to Seletar Expressway, a new road between MacRitchie Viaduct and Adam Flyover, and an expansion of the Kallang-Paya Lebar Expressway/Tampines Expressway interchange (which includes a link road to Punggol Central).

Two weeks ago, a section of the Changi viaduct being built by local contractor Or Kim Peow and engineering consultancy CPG gave way. One worker was killed and 10 were injured.

The BCA said it instructed the parties involved in the Changi viaduct project "to install props and supports for the adjacent beams or girders as a precautionary measure immediately after the incident".

"There is no further risk to the public as the props had already been installed."

The authority said it is still investigating the cause of the collapse, with preliminary findings pointing to corbels - angled concrete structures built to support heavy beams - giving way.

The LTA also said that cracks were found at 11 spots on corbels across the six viaduct sections at Changi.

On Tuesday, Manpower Minister Lim Swee Say gave another glimpse into what investigators had uncovered so far.

Speaking to an audience of some 1,400 construction industry players at the annual Workplace Safety and Health awards at Resorts World Sentosa, Mr Lim said: "One thing for sure is that this is a man-made incident that could have been avoided if everyone involved in this project had paid enough attention to the design and construction of the viaduct and the safety of workers."

Meanwhile, The Straits Times understands that the Manpower Ministry has inspected a number of LTA road project sites since the viaduct collapsed. The checks were to ensure adequate measures were in place for workers' safety and health.